1. Field of the Invention
This invention generally relates to an apparatus and method for controlling an image display, which utilizes at least one reference object to generate modulated spectrum signals and an image sensor to detect the spectrum signals and to calculate an image variation of the reference object so as to control the image display.
2. Description of the Related Art
A conventional cursor control method disclosed in Taiwan Patent Publication No. 200540687, entitled “Apparatus for cursor control and method thereof” provides a hand-held device for controlling a cursor in a display. First, a movement is detected by the hand-held device. A position differential is calculated according to the detected movement. Then, the hand-held device wirelessly transmits the position differential to a specific device to control the cursor activity accordingly, and operate an application on the specific device according to the cursor activity. However, in practical use, when the hand-held device is utilized to detect an image area, the position of the detected image on a sensing array of the hand-held device may be affected by a distance between the hand-held device and the object to be photographed, and also be affected by a rotating angle of the hand-held device while photographing. If the distance and the rotating angle are not corrected, error control of the cursor activity may occur during operation. In addition, since the detected image includes all objects inside the viewing angle of the hand-held device, the image recognition is relatively complicated.
In order to solve the problem existing in the art, in the commonly owned Taiwan Patent Application No. 095116011, entitled “Pointer positioning apparatus and method” and Taiwan Patent Application No. 0951149408, entitled “Cursor controlling method and apparatus using the same”, at least one reference object is utilized for generating an IR signal, e.g. 940 nm wavelength, and an IR filter is integrated on an image sensor to filter out optical signals outside the band of the IR signal such that an image sensor can only detect IR signals generated from the reference object thereby decreasing the complexity of image recognition. An image display can be controlled according to an image variation, e.g. position displacement, of the image of the reference object detected by the image sensor. However, although the function of the image sensor will not be interfered while operating under a fluorescent light (350 to 750 nm wavelengths) environment, it will still be interfered by a halogen lamp light source (350 to 1100 nm wavelengths) which exists in the same environment, especially when the halogen lamp light source is placed nearby the reference object. The image detected by the image sensor through the IR filter will include both the reference object and the halogen lamp light source such that error recognition will occur during image post-processing and hence it may be unable to correctly control the image display. In addition, the sunlight is another light source which may influence the normal function of the control apparatus.
Accordingly, there exists a need to further improve the conventional image display control apparatus so as to improve the control accuracy thereof.